Python GUI Programming - A Complete Reference Guide

The plot_checks table

Plot checks are the actual data records collected at individual plots. These are part of a lab check, and so must refer back to an existing lab check.

We'll begin with the primary key columns:

CREATE TABLE plot_checks(date DATE NOT NULL, time TIME NOT NULL,lab_id CHAR(1) NOT NULL REFERENCES labs(id), plot SMALLINT NOT NULL,

This is the primary key of a lab_check table plus a plot number; its key constraints look like this:

PRIMARY KEY(date, time, lab_id, plot),
FOREIGN KEY(date, time, lab_id)
    REFERENCES lab_checks(date, time, lab_id),
FOREIGN KEY(lab_id, plot) REFERENCES plots(lab_id, plot),

Now we can add the attribute columns:

seed_sample CHAR(6) NOT NULL, humidity NUMERIC(4, 2) CHECK (humidity BETWEEN 0.5 AND 52.0), ...